Case bolts!! WTF??

[cosmiccharlie]

Since you followed the Clymer to a "T" you must already know that the torq spec for the 6mm length bolts are half the value of the 8mm length bolts and I am wasting my breath.




psssst....fess up, you snapped the short bolts.

Yes you are wasting your breath!!  Short bolts are fine!  Three long bolts broke! 

[Alphamazing]

Personally, I wouldn't think they'd need to be replaced every time the case is opened.

[Trwhouse]

Hey there,
For better, stainless steel bolts for your bike, check out my recent post:

http://gstwins.com/gsboard/index.php?topic=34795.0

I found a great place to buy stainless steel fasteners for my GS500.
Go to:
http://www.westcoastmc.com/store/
I found this guy on ebay when I was looking recently for stainless steel allen head bolts for my bike.
He sells whole kits or individual fasteners.
His phone number and contact info are on his site -- 604 637-7854. He's in Washington state.
I bought a set of stainless allen head bolts for my engine and a separate set for the carbs.
All nice quality and cheap!
Less than $25 for all including shipping.
Tell him what you need as far as case bolts and he will put a full set together for you with standard hex heads, in high quality stainless bolts. Tell him what you want and he will help.
Highly recommended.

Yours,
Todd

[NiceGuysFinishLast]

OH NOES. PANDY CALLED ME A CHILDREN! WHATEVER SHALL I DO?

Seriously.. I was just in an @$$hole mood tonight. So my bad. But c'mon.. it's Alpha.. ALL of his posts are inflammatory, in some form, but he usually has some damn good info too. I do the same thing, but without providing info. I'm just an @$$hole.

[ducati_nolan]

Did you torque the bolts down in two or three steps? Or did you just start cranking them down to the full torque value?

After breaking a head bolt on a car, now I'm really carfull about first of all using the correct lubricant on the threads. I then get all the bolts just snug, then to 1/3 of their final torque, then 2/3, then the full torque value. I then go over all the bolts one more time at the full torque value to make sure I haven't missed one.

Another thing is that some torque wrenches can be pretty inacurate, especially cheap ones, old ones, or dammaged ones. I'd check out your wrench before using it to tighten your new bolts.

Good luck.

[Jay_wolf]

Ive Seen Full Sets Of SS Engine Bolts On Ebay , for like 12 pounds, wouldnt worry about it

[zephler]

tuff luck mate   

did you use a smaller sized torque wrench? I once broke two bolts putting OHC gear back on a toyota engine, the large torque wrench (used for the head bolts) was too much for the smaller bolts and broke them off before the wrench went click to stop  that blew man   

[cosmiccharlie]

I was using a small torque wrench. 

Should I buy stock bolts or try and get the guy mentioned above to put together a stainless set?

[NiceGuysFinishLast]

I've seen the stainless steel set on ebay and thought about it... It's probably about the same cost as going OEM, if I had to guess. Your call though.

[sledge]

Charlie?
The longer a bolt is, the more likely it is to shear. This is an important factor with larger diameter bolts. Your torque wrench,  if servicable and correctly set should have clicked out way before the applied torque got anywhere near the bolt shear limit regardless of its physical size....... Some thoughts:

Did you get any sealant in the holes and cause a hydraulic-lock?

Did you confuse lbs/ft with N/m (or vice-versa) on the torque-wrench scale
.
Are you 100% sure the bolts are in the correct holes with regard to length and didnt bottom-out?

Any one of these conditions can lead to a shear.

When reasseambling, run a suitable size Plug-tap down each hole to clean out the threads before you fit the bolts. Make sure the bolts go fully home under finger pressure without binding. The bolts will have probably broken on the juncture between the shank and the thread, this is the weakest point of any bolt. If the bolts have broken flush with the casing dont try and drill them out yourself or waste your time and money on Easy-outs. Get professional advice and help. The bolts need to be machined out and a helicoil insert fitted. The cases are alloy and the bolts steel, a twist-drill in a Black and Decker will wander into the softer metal unless very VERY carefully controlled. You only get one shot , and if you screw-up the damage will be very expensive to repair.

[cosmiccharlie]

Charlie?
The longer a bolt is, the more likely it is to shear. This is an important factor with larger diameter bolts. Your torque wrench,  if servicable and correctly set should have clicked out way before the applied torque got anywhere near the bolt shear limit regardless of its physical size....... Some thoughts:

Very true, but it did not click.  Maybe the bolts were weakened by age and heat?  idk

Did you get any sealant in the holes and cause a hydraulic-lock?

I don't think so, but it is a possibility

Did you confuse lbs/ft with N/m (or vice-versa) on the torque-wrench scale

No checked, and double checked.

Are you 100% sure the bolts are in the correct holes with regard to length and didnt bottom-out?

Yes, 100%

Any one of these conditions can lead to a shear.

When reasseambling, run a suitable size Plug-tap down each hole to clean out the threads before you fit the bolts. Make sure the bolts go fully home under finger pressure without binding. The bolts will have probably broken on the juncture between the shank and the thread, this is the weakest point of any bolt. If the bolts have broken flush with the casing dont try and drill them out yourself or waste your time and money on Easy-outs. Get professional advice and help. The bolts need to be machined out and a helicoil insert fitted. The cases are alloy and the bolts steel, a twist-drill in a Black and Decker will wander into the softer metal unless very VERY carefully controlled. You only get one shot , and if you screw-up the damage will be very expensive to repair.

I will keep all that in mind when I reassemble.  I have not pulled the cases back apart yet.  Hopefully the bolts did not break flush with the case. 

[dgyver]

Do not use any other type of bolt (ie stainless steel) for the cases than what is supplied. Using a stronger grade bolt risks stripping the threads in the case. They are soft for a reason. Stripping thread in the case is a lot worse than breaking replaceable bolts.

I misread the torque setting when I was reinstalling an oil pan once. Luckily the bolts stretched and did not damage the case. Other than that, I have not snapped any motor bolts...brake rotor bolts are another story.

Also, the lower/end range of torque wrenches are not all that accurate. It is possible that you unintentionally over torqued them.

[cosmiccharlie]

Also, the lower/end range of torque wrenches are not all that accurate. It is possible that you unintentionally over torqued them.

Very possible.  I have already ordered OEM bolts from Bike bandit.  Thanks for all the help guys!

[RVertigo]

Man...  When good threads go bad...



Anyway....   Are the bolts on the Magnito/Clutch side covers the same?  Like...  Gonna snap on me?    

I've already snapped three bolts on the GS damnit...

[dgyver]

I have not had any problems with the case cover bolts, so far.

[sledge]

The more nuts and bolts you tighten/loosen, the less likely it is you will shear any. Over a long period of time Engineers, mechanics, techies etc  develop a kind of "Sixth sense" and can tell by the amount of force applied to the fastening, the feel of the tool in the hand, and the amount of flex if something is going to snap or cross- thread.